There is a row of m houses in a small city, each house must be painted with one of the n colors (labeled from 1 to n), some houses that have been painted last summer should not be painted again.
A neighborhood is a maximal group of continuous houses that are painted with the same color.
- For example: houses = [1,2,2,3,3,2,1,1] contains 5 neighborhoods [{1}, {2,2}, {3,3}, {2}, {1,1}].
Given an array houses, an m x n matrix cost and an integer target where:
- houses[i]: is the color of the house i, and 0 if the house is not painted yet.
- cost[i][j]: is the cost of paint the house i with the color j + 1.
Return the minimum cost of painting all the remaining houses in such a way that there are exactly target neighborhoods. If it is not possible, return -1.
2209. Minimum White Tiles After Covering With Carpets
You are given a 0-indexed binary string floor, which represents the colors of tiles on a floor:
- floor[i] = ‘0’ denotes that the ith tile of the floor is colored black.
- On the other hand, floor[i] = ‘1’ denotes that the ith tile of the floor is colored white.
You are also given numCarpets and carpetLen. You have numCarpets black carpets, each of length carpetLen tiles. Cover the tiles with the given carpets such that the number of white tiles still visible is minimum. Carpets may overlap one another.
Return the minimum number of white tiles still visible.
2208. Minimum Operations to Halve Array Sum
You are given an array nums of positive integers. In one operation, you can choose any number from nums and reduce it to exactly half the number. (Note that you may choose this reduced number in future operations.)
Return the minimum number of operations to reduce the sum of nums by at least half.
2207. Maximize Number of Subsequences in a String
You are given a 0-indexed string text and another 0-indexed string pattern of length 2, both of which consist of only lowercase English letters.
You can add either pattern[0] or pattern[1] anywhere in text exactly once. Note that the character can be added even at the beginning or at the end of text.
Return the maximum number of times pattern can occur as a subsequence of the modified text.
A subsequence is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.
2206. Divide Array Into Equal Pairs
You are given an integer array nums consisting of 2 * n integers.
You need to divide nums into n pairs such that:
- Each element belongs to exactly one pair.
- The elements present in a pair are equal.
Return true if nums can be divided into n pairs, otherwise return false.
1606. Find Servers That Handled Most Number of Requests
You have k servers numbered from 0 to k-1 that are being used to handle multiple requests simultaneously. Each server has infinite computational capacity but cannot handle more than one request at a time. The requests are assigned to servers according to a specific algorithm:
- The ith (0-indexed) request arrives.
- If all servers are busy, the request is dropped (not handled at all).
- If the (i % k)th server is available, assign the request to that server.
- Otherwise, assign the request to the next available server (wrapping around the list of servers and starting from 0 if necessary). For example, if the ith server is busy, try to assign the request to the (i+1)th server, then the (i+2)th server, and so on.
You are given a strictly increasing array arrival of positive integers, where arrival[i] represents the arrival time of the ith request, and another array load, where load[i] represents the load of the ith request (the time it takes to complete). Your goal is to find the busiest server(s). A server is considered busiest if it handled the most number of requests successfully among all the servers.
Return a list containing the IDs (0-indexed) of the busiest server(s). You may return the IDs in any order.
1756. Design Most Recently Used Queue
Design a queue-like data structure that moves the most recently used element to the end of the queue.
Implement the MRUQueue class:
- MRUQueue(int n) constructs the MRUQueue with n elements: [1,2,3,…,n].
- int fetch(int k) moves the kth element (1-indexed) to the end of the queue and returns it.
1687. Delivering Boxes from Storage to Ports
You have the task of delivering some boxes from storage to their ports using only one ship. However, this ship has a limit on the number of boxes and the total weight that it can carry.
You are given an array boxes, where boxes[i] = [portsi, weighti], and three integers portsCount, maxBoxes, and maxWeight.
- portsi is the port where you need to deliver the ith box and weightsi is the weight of the ith box.
- portsCount is the number of ports.
- maxBoxes and maxWeight are the respective box and weight limits of the ship.
The boxes need to be delivered in the order they are given. The ship will follow these steps:
- The ship will take some number of boxes from the boxes queue, not violating the maxBoxes and maxWeight constraints.
- For each loaded box in order, the ship will make a trip to the port the box needs to be delivered to and deliver it. If the ship is already at the correct port, no trip is needed, and the box can immediately be delivered.
- The ship then makes a return trip to storage to take more boxes from the queue.
The ship must end at storage after all the boxes have been delivered.
Return the minimum number of trips the ship needs to make to deliver all boxes to their respective ports.
Given an integer array nums, in which exactly two elements appear only once and all the other elements appear exactly twice. Find the two elements that appear only once. You can return the answer in any order.
You must write an algorithm that runs in linear runtime complexity and uses only constant extra space.